1. Field of the Invention
The present invention relates to a sheet processing apparatus for performing post-processing of a sheet discharged from an image forming apparatus such as a copying machine, a printer or a compound machine.
2. Description of the Related Art
In recent years, some image forming apparatuses are provided with a sheet post-processing apparatus adjacently to a paper discharge unit of an image forming apparatus main body in order to perform post-processing such as sorting of sheets after image formation or stapling of sheets.
In the case where the post-processing such as the stapling is performed on the sheet transported from the image forming apparatus, the sheet is often charged with static electricity. When the sheet is charged, a jam occurs or a trouble occurs in the post-processing. Besides, a discharge operation after the post-processing is not performed well, and defective discharge is liable to be caused. Thus, some post-processing apparatuses are provided with an electricity removing member.
JP-A-2004-99200 discloses a sheet post-processing apparatus for performing a binding processing of sheets. In this sheet post-processing apparatus, after plural sheets are bound, they are discharged by a paper discharge roller, and an electricity removing brush is provided in a sheet transport path.
JP-A-10-250911 discloses a sheet post-processing apparatus for performing post-processing such as stapling. In this example, there is included a guide member to guide a sheet to a processing tray for the post-processing, and an electricity removing member is provided in this guide member.
However, in the above examples, since the system is such that the electricity removing member comes in contact with only one surface of the transported sheet, when plural sheets overlap each other, a satisfactory electricity removing effect can not be obtained.
The invention provides a sheet processing apparatus in which the electrostatic charging of a sheet as stated above is reduced.